Temperature regulator for secondary volatile refrigerant circuit



y 27, 1952 c. F. ALSING 2,598,335

TEMPERATURE REGULATOR FOR SECONDARY VOLATILE REFRIGERANT CIRCUIT Filed June 17, 1947 2 SHEETS-SHEET 1 'vllllll',

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WITNESSES: INVENTOR WW CARL EHLSING cliHLj.

ATTORNEY May 27, 1952 c. F. ALSING TEMPERATURE REGULATOR FOR SECONDARY VOLATILE REFRIGERANT CIRCUIT 2 SHEETS-SI-IEET 2 Filed June 17, 1947 INVENTOR CARI.

F. BLSING -M ATTORNEY Patented May 27, 1952 TEMPERATURE REGULATOR FOR SECOND- ARY VOLATILE REFRIGERAN T CIRCUIT Carl F. Alsing, Wilbraham, Mass., assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a, corporation of Pennsylvania Application June 1'7, 1947, Serial No. 755,090

7 Claims. (01. 624) This invention relates to secondary volatile refrigerant circuits and, more especially. to a temperature regulator for such circuits.

It is an object of the invention to provide a novel regulator for varying the heat-transferring action of a secondary volatile refrigerant circuit.

It is a further object of the invention to provide a novel regulator of the type described which has no moving parts to effect a variation in its heat-transferring action.

These and other objects are efiected by the invention as will be apparent from the following description and claims taken in connection with the accompanying drawings, forming a part of this application, in which:

Fig. 1 is a vertical section of a refrigerator cabinet embodying the invention, the cooling elements being shown somewhat schematically;

Fig. 2 is an enlarged sectional view of the regulating receptacle of this invention showing one phase of its operation;

Fig. 3 is a view similar to Fig. 2 but showing another phase of the operation of the receptacle;

Fig. 4 is a section on the line IV-IV of Fig. 3;

Fig. 5 is a section on the line V-V of Fig. 1;

Fig. 6 is a vertical sectional view of a refrigerator embodying a modification of the invention;

Fig. 7 is an enlarged sectional view of the regulating receptacle shown in Fig. 6; and

Fig. 8 is an enlarged sectional view of a modification of the regulating receptacle shown in Fig. 6.

In the drawings, the reference numeral I0 designates the food storage cabinet of a refrigerator, the cabinet having thermally-insulated walls l2 and a door [4. A horizontal partition l6 divides the cabinet in into an upper compartment I 8 for the storage of frozen food and into a lower compartment 20 for ordinary refrigerated storage. A machine compartment 22 is located below the food storage compartment II] which compartment 22 houses the refrigerant liquefying apparatus of the refrigerator.

The upper compartment [8 is cooled by a refrigerant evaporator 24 in the form of a tube. The vaporized refrigerant is removed from the evaporator 24 through a suction tube 26 by a compressor (not shown) located in a sealed casing 28. The compressor is driven by an electric motor (not shown) also located in the sealed casing 28. The compressed refrigerant vapor is conveyed from the compressor through a. tube 30 to an airicooled condenser 32. Cooling air ambient the'cabinet I 0 is drawn through the louver 34 in the machine compartment 22 and through the condenser 32 by an electrically-driven fan 36. The cooling air passes over the sealed casing 28 and leaves the machine compartment 22 through the louver 38. The refrigerant vapor is liquefied in the condenser 32 and is forced through a capillary tube 40 to the lower end of the evaporator 24 wherein it vaporizes and cools the compartment l 8 to a temperature of about 0 F. Portions of the capillary tube 46 and the suction tube 26 are in heat-transfer relation.

The electric motor (not shown) in the sealed casing 28 is supplied with electrical energy through leads 42. A thermostatically-controlled switch 44 is located in one of the leads 42 and is actuated through a tube 45 by a temperatureresponsive bulb 46 located in the upper compartment [8. Such thermostats are well known in the art.

The lower compartment 20 is cooled by a secondary volatile refrigerant circuit which includes a receptacle 50 located in the thermal insulation of the rear wall of the food storage cabinet It. The receptacle 50 is divided by a horizontal partition 52 into an upper compartment comprising a refrigerant transfer chamber 54 and a lower compartment comprising a liquid refrigerant storage vessel 56. The partition 52 includes an elevated portion in its center having an orifice 58 in its upper wall. A needle 60 is secured to the center of the upper wall 62 of the receptacle 50 and enters the orifice 58 with its pointed end to restrict the flow of fluid through the orifice 58. The upper wall 62 is rendered flexible by a circular groove 64, and its center together with the needle 60 may be raised or lowered by turning an adjustment screw 66. The screw 66 is in threaded engagement with the central portion of a bail 66, the ends of which are secured to the side walls of the receptacle 55. A secondary evaporator 16 is located in the lower compartment 20 to cool it to a temperature of about 40 F. The secondary evaporator T0 is in the form of a sinuous tube, the upper end 12 of which communicates with the upper portion of the transfer chamber 54 and the other end 14 of which communicates with the lower portion of the transfer chamber 54.

A blind tube 16 has an upper portion 18 in heat-transfer relation with the primary evaporator 24. This upper portion 18 constitutes the secondary condenser of the secondary system. The lower portion of the blind tube 15 enters the transfer chamber 54 near the upper wall 52 and continues downwardly through the partition 52 t0 the lower portion of the storage vessel 56.

This tube portion 80 is in fluid-tight engagement with the wall of the transfer chamber 54 and with the partition 52. An opening 82 is located in the tube portion 80 immediately above the partition 52 and a second opening 84 is located in the tube portion 80 above the opening 82 to communicate with the upper portion of the transfer chamber 54. The bottom wall of the storage vessel 56 is in heat-transfer relation with the capillary tube 40. The secondary system evacuated and a quantity of refrigerant is introduced therein which quantity is such that when the refrigerator is in operation and all of the refrigerant liquid is in the storage vessel 56 the liquid level of the refrigerant liquid will not be above the lower portion of the partition 52'. This condition is shown in Fig. 2.

Operation The secondary volatile refrigerant circuit and its regulating device operates as follows: Refrig erant vapor'is condensed by the upper portion 18 of the tube '16 and flows downwardly into the storage vessel 55. If no heat is applied to the storage vessel 56 by the capillary tube 40, the refrigerant liquid will remain in the vessel 56 as is shown in Figure 2. A small amount of this liquid will vaporize and pass through the orifice 58 and the opening 84 to the condensive portion 18 of the tube 16 but on being condensed will again return to the vessel 56. Under these conditions the lower compartment 20 is not refrigerated because no refrigerant liquid is supplied to the secondary evaporator I0.

If heat is applied to the vessel 56 by the capillary tube 40, more of the refrigerant liquid in the vessel 56 will vaporize. The restrictive effect of the orifice 58 is so adjusted by the screw 66 that the additional flow of vapor causes a back pressure to form in the vessel 56 which pressure is higher than that in the secondary evaporator 10. This pressure causes the refrigerant liquid to rise in the lower portion 80 of the tube T to a level above the opening 82 as illustrated in Figure 3. The liquid, thereupon, runs through the opening 82 into the transfer chamber 54 and flows downwardly through the tube Hi into the secondary evaporator 10. The opening 82 thus forms a spillway for the liquid. The refrigerant liquid absorbs heat from the lower compartment 20, vaporizes, and passes through the upper end I2 of the evaporator I0 into the transfer chamber 54 and then through the opening 86 to the condensive portion 18 of the tube I0. On being condens'ed, the liquid runs down through the tube 16, and since its entrance into the vessel 56 is opposed by the higher pressure therein, the liquid flows through the opening 82, over the partition 52, and downwardly through the end 14 and into the evaporator 10. This action continues and cools the secondary evaporator 10.

The degree of cooling effected in the secondary evaporator '10 varies with the quantity of refrigerant liquid transferred to it through the end "I4 by the receptacle 50. with the temperature of the capillary tube 40 and this in turn varies with the temperature of the room air which cools the condenser 32 and upon the proportion of the running time of the primary refrigerating apparatus to its idle time. This proportion also varies with the temperature of the room in which the refrigerator is located so that the quantity of cooling effected by the secondary evaporator varies substantially with the room temperature. The higher This quantity varies full the room temperature, the greater will be the cooling effect of the evaporator I0. This greater cooling efiect tends to offset the greater heat leakage into the compartment 20 in the higher room temperature so that the variations in the cooling eifect of the evaporator 10 tend to maintain the temperature of. the lower compartment 20 constant in varying room temperatures. The substantially constant temperature at which the lower compartment 20 is maintained may be changed by adjusting the screw 06 which may be turned by any suitable means.

Theregulating apparatus of this invention can also be actuated: by exposing the vessel 55 to the room. air so" that the pressure within the vessel becomes responsive to the temperature of the room air. This, however, transfers heat into the cabinet and is not favored.

Modifications A modification of the invention is shown in Figs. 6 and 7; In these figures parts identical with those shown in the previous modification are provided with the same reference numerals. Referring to Fig. 6, the reference numeral I00 designates a secondary evaporator similar in function to the evaporator 10 of Fig. 1. The upper end of the evaporator I00 is joined by a tube I02 to the upper end of the tube I04 which constitutes the secondary condenser so that the refrigerant vaporized in the secondary evaporator I00 passes directly to the secondary condenser I04. The refrigerant condensed in the secondary condenser I04 flows through a tube I06 to the lower portion of a vessel I08which vessel has a function similar to the vessel of the previously-described modification. A vertical tube Ii 0 communicates through an upwardlyarched portion I I2 with a portion of the tube I06 located in the upper part of the vessel I08. This tube IIO communicates with the lower end of the evaporator I00. The upper portion of the vessel I08 also communicates through a tube [l3 and a needle valve II4 with the upper portion of the secondary evaporator I00. The quantity of refrigerant in the secondary system is such that the refrigerant liquid in the system, if entirely contained in the vessel I08, will have an upper level H0 which is below the arched portion N2 of the tube I i 0 so that the liquid does not run into the tube H0. This condition is shown in Fig. 'l.

The operation of this modification is similar to the modification previously described. The heat of the capillary tube 40 vaporizes some of the liquid in the vessel I08 and this vapor passes through the tube H3 and the needle valve II to the secondary condenser I04 wherein it is liquefied and is returned to the vessel I08 through the tube I06. When the heat of the capillary tube 00 exceeds a predetermined degree, the refrigerant vapor passing through the needle valve H4 will encounter sufficient resistance to create a back pressure in the vessel I08, which back pressure elevates the refrigerant liquid level in the tube I06 to above the arched portion N2 of the tube I I0 so that the refrigerant liquid will run into the evaporator I00. The lower inner surface of the arched portion II2 thus forms a spillway for the liquid.

The refrigerant liquid vaporized in the evaporator I00 will pass upwardly directly to the secondary condenser X02, will be liquefied therein, and will flow through tubes I06 and H0 to the evaporator I00. The quantity of refrigerant liquid expelled from the vessel H38 will depend upon the quantity of heat transmitted to the vessel 18' by the capillary tube 413 at any given setting of the needle valve 1 hi. The needle valve I [4 may be adjusted to vary the quantity of refrigerant liquid supplied to the evaporator I06 for any given temperature of the capillary tube 49.

A modification of the piping in the vessel N8 is shown in Fig. 8. In this modification, the tube 126 which corresponds to the tube 1 I of the previous modification communicates directly with a lower portion of the vessel I08 through an elevated portion l22. This figure shows the vessel E83 under pressure so that the liquid level in the tube its is elevated and the refrigerantliquid runs over the elevated portion I22 of the tube 529. The action of this modification differs from that of the modification shown in Fig. 7 in that a siphoning action may take place across the elevated portion I22 whenever the refrigerant liquid starts to flow through the same. This siphoning action will draw out some of the refrigerant liquid from the vessel 108 so that the liquid supplied to the evaporator H39 will be of a pulsating character.

The general action of the three modifications shown is that the refrigerant liquid condensed by the secondary condenser flows into the liquid storage vessel and will be substantially completely trapped therein if the storage vessel is not heated. If the vessel is heated in response to increases in the room temperature, some of the refrigerant liquid will be forced from the vessel over an elevated spillway and will then run into the secondary evaporator. Also, when the vessel i heated, liquid refrigerant from the condenser will either by-pass the vessel completely and flow into the secondary evaporator or will merely flow through the vessel on its way to the secondary evaporator.

It will be apparent from the above that this invention provides an automatic regulatin device for a secondary volatile refrigerant circuit which has no operating moving parts and which tends to maintain the chamber cooled but at a substantially constant temperature in spite of varying ambient temperatures of the refrigerated cabinet. The invention also provides a manual adjustment for changing the substantially constant temperature at which the chamber is maintained.

While I have shown my invention in several forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modifications without departing from the spirit thereof.

What I claim is:

1. In a refrigerating system, the combination of a cabinet having a space to be refrigerated, a refrigerant evaporator for abstracting heat from media in said space, a refrigerant condenser disposed exteriorly of the space, a vessel for containing a body of liquid refrigerant, means for applying heat to said vessel in proportion to the temperature of the atmosphere ambient said cabinet for varying the temperature and pressure of said body of refrigerant directly in response to changes in temperature of the ambient atmosphere, a conduit structure connected to the condenser and terminating in a lower region of the vessel for draining condensed refrigerant by gravity from the condenser to the vessel, means defining an overflow passage for the body of liquid refrigerant in the vessel, means for draining refrigerant, overflowing through said passage, by

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, 6 gravity to the evaporator, means for conveying vaporized refrigerant from the evaporator to the condenser and adjustable valve means connecting an upper region of said vessel and said vaporized refrigerant conveying means for the passage of vaporized refrigerant.

2. In a refrigerating system, the combination of a cabinet having a space to be refrigerated, a refrigerant evaporator for abstracting heat from media in said space, a refrigerant condenser disposed exteriorly of the space, a vessel for containing a body of liquid refrigerant, means for applying heat to said vessel in proportion to the temperature of the atmosphere ambient said cabinet for varying the temperature and pressure of said body of refrigerant directly in response to changes in temperature of the ambient atmosphere, a conduit structure connected to the condenser and terminating in a lower region of the vessel for draining condensed refrigerant by gravity from the condenser to the vessel, said conduit structure having an overflow opening in an intermediate portion thereof for condensed refrigerant, means for draining refrigerant, overflowing through the opening, by gravity to the evaporator, means for conveying vaporized refrigerant from the evaporator to the condenser and means for defining an orifice for the passage of refrigerant vapor from the vessel to said vaporized refrigerant conveying means.

3. In a refrigerating ystem, the combination of a cabinet structure having an enclosed space for media to be cooled, a condenser, an evaporator for cooling the media in said space, a compartmented vessel having first and second chambers, a conduit structure for conveying liquid refrigerant from the condenser to said second chamber, said conduit structure having an intermediate portion in open communication with said first chamber for the passage of gaseous refrigerant from the first chamber to the conduit structure, said intermediate portion of the conduit structure providing for the overflowing of liquid refrigerant from the conduit structure to the first chamber, means for conveying liquid refrigerant from the lower region of the first chamber to the evaporator, means for discharging gaseous refrigerant from the evaporator to the first chamber, means for applying heat to said vessel in proportion to the temperature of the ambient atmosphere exteriorly of the cabinet structure for varying .the pressure of the refrigerant in said second chamber directly with changes in temperature of said ambient atmosphere and means defining a restricted orifice providing communication between said first and second chamber.

4. The combination as claimed in claim 3 wherein said first chamber is elevated with respect to the second chamber.

5. The combination as claimed in claim 3 including adjustable means disposed, at least in part, exteriorly of the vessel for adjusting the fiow area of said orifice.

6. In a refrigerating system, the combination of a cabinet defining a space to be refrigerated, a condenser, an evaporator for cooling media in said space, a vessel having a partition dividing the vessel into upper and lower chambers, said partition having an orifice for the flow of refrigerant vapor from the lower chamber to the upper chamber, a conduit structure communicating with said condenser and, extending downwardly therefrom through said upper chamber and terminating adjacent the bottom region of the lower chamber for the delivery of condensed refrig- I'ZT remc her er aid qqndkliiz st u mv ser av an o er le t pe nether i r el y of 0, detesed refrig m; to the lower regiorr or the upperchamlqenseid, ecnduit structure haying a second ogening; therein communicating with; arr upper region of the upper chamberfor the passage o refrigerant vapor tq the conduit structure, means for ccnveying' condensed refrigerant from the- Lower; region; of the upper chamberto the evaporet n. m an for nn in or e frigerent from the eva-pprator to the upper hemb n. nd; means f ap yi h o. ai vessel in prepcrtiqrr to the temperature of the am i nt. atm h re ext r r o Said. cab n t f r: ryin the nressure o h re i nt in said lower-5 chamber directly in response tq tweeter-i Q he m e t e m nne e.

7. The, cqrghhgetign es claimed in claim 6 inudin qlfes ahle di s d at least n part, e zgteri orly cf; the vessel forvaryin the flow a Q id aif-lee CARL F. ALSING.

EEEERE E S CITED The. following references are of record in the file of this patent;

UNITED S A ES. PATENT$ 

